Stylet and connector therefor

ABSTRACT

A stylet which comprises a stylet assembly body and a connector for connecting the stylet to a catheter. The stylet body has a piece of wire bent double and twisted together to form a rounded end serving as a distal end at one end. The connector has a stylet connecting part for holding a proximal end of the stylet body. The connector also holds the catheter to prevent the catheter from slipping from the stylet during use.

This application is a continuation, of application Ser. No. 08/600,046filed on Feb. 12, 1996, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a stylet assembly including a stylet,or stylet body, used for insertion of a catheter into the blood vesseland to a connector for holding a stylet and connecting it to a catheter.More particularly, it relates to a stylet to be inserted into a lumen ofa venous catheter for total parenteral nutrition to give a desiredrigidity to the catheter and to a connector for holding the stylet inthe lumen thereof, which makes it possible to allow a medical solutionto flow into the catheter through the lumen thereof.

2. Description of the Prior Art

When inserting a venous catheter for total parenteral nutrition or anendotracheal tube, it is general practice to insert a metal wire or astylet into a catheter to give some rigidity to the catheter or tubesince such a catheter is too soft to insert into the blood vessel ortrachea without causing bending of the catheter. The stylet is bent intoa desired shape as occasion demands. For example, in case ofintratracheal intubation, the stylet is bent into a shape correspondingto the shape of respiratory tract of a patient whose larynx beingexpanded.

In general, however, the stylet is of a metal such as stainless steeland has an acute-angled end. Thus, the stylet of the prior art hasdisadvantages that blood vessel walls or trachea walls may be injured bythe distal end of the stylet protruded from the catheter duringinsertion of the catheter. Further, it is occasionally required to usethe catheter filled with heparinized saline to perform primingoperations. In such a case, it is necessary to remove the stylet fromthe catheter to fill the catheter with heparinized saline. In addition,it requires a great deal of skill to insert the stylet of the prior artinto a correct position of the superior vena cava through the subclavianvein.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a styletassembly which is prevented from injuring blood vessels.

Another object of the present invention is to provide a stylet assemblywhich facilitates correct and safe insertion a catheter to a desiredposition with ease.

Still another object of the present invention is to provide a styletconnector which facilitates priming operations without removal of astylet from a catheter.

According to the present invention, there is provided a stylet assemblycomprising a stylet body and a connector for connecting the stylet to acatheter, said stylet body being composed of a piece of wire bent doubleand twisted together to form a rounded end serving as a distal end atone end, said connector having a stylet body connecting portion forholding a proximal end of said stylet body and means for fixedly holdingthe catheter to prevent the catheter from slipping from the styletduring use.

In a preferred embodiment, the stylet body is bent at a distal portionat a certain angle to allow the catheter to be correctly inserted into adesired place in the blood vessel. In this case, the connector may beprovided with a certain mark indicating a bending direction of thestylet body.

According to the present invention, there is also provided a connectorcomprising a tubular body having at one end a stylet body connectingportion and at the other end an inflow port for medical solution, saidstylet body connecting portion holding the stylet body and providingpassages for flow of a medical solution from a lumen thereof withoutremoval of the stylet when performing the priming operation.

The stylet connector further includes a sleeve rotatably mounted on thedistal end of the tubular body to form a means for fixing a catheter.Preferably, the stylet body connecting portion is provided integrallyand coaxially with the tubular body.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention will beexplained in detail, making reference to the accompanying drawings whichshow one preferred embodiment of the present invention, and in which:

FIG. 1 is a plan view illustrating a stylet assembly according to thepresent invention;

FIG. 2 is an enlarged view of a distal end of the stylet, or styletbody, shown in FIG. 1;

FIG. 3 is an enlarged view of a connector used in the stylet assembly ofFIG. 1;

FIG. 4 is a sectional view taken along a line X—X in FIG. 3;

FIG. 5 is an enlarged side view of the connector taken from thedirection of an arrow A shown in FIG. 4;

FIG. 6 is a plan view illustrating the stylet assembly of FIG. 1 with acatheter into which the stylet is inserted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIGS. 1, 3, 4 and 5 there is shown a stylet assembly Saccording to the present invention, which comprises a stylet body 1 anda stylet connector 2 for attachment of the stylet to a catheter. Thestylet 1 is preferably bent at a certain angle at a certain position toform an angled, or offset distal end portion 11, though the stylet body1 may be formed in a straight line. The connector 2 comprises a tubularmember 20 having at one end a stylet body connecting portion 24 and atthe other end an inflow port 25 for a liquid medicine. The connector 2is provided with a sleeve 23 rotatably mounted on the tubular member 20on the side of its distal end to form a means for fixing a catheter 3,as shown in FIG. 6. In use, the stylet body 1 is inserted into a lumenof the catheter 3 through a connector 31 of the catheter and then fixedto the catheter 3 by engagement of the connector 31 with thecatheter-fixing means 23.

As best shown in FIG. 2, the stylet body 1 is composed of a piece ofwire bent double and twisted together to form a hairpin or rounded end12. This stylet body may be prepared, for example, by bending a piece ofstainless steel wire double to form a rounded distal end 12 and thentwisting the doubled wire together. The stylet body 1 is so attached tothe connector 2 that the rounded end 12 becomes an distal end of thestylet body 1. The pitch P of the twisted wire varies with material andsize of the wire. In case of a piece of stainless steel wire with adiameter of 0.2 mm, it is preferred to twist the wire at a pitch of 5 to8 mm, preferably, 6 mm. Although the stylet body 1 may be used in astraight form, the stylet body 1 of this embodiment is bent at a certainposition away from the distal end at a certain angle so that thecatheter can be correctly inserted into a desired place in the bloodvessel of a patient. The size of the stylet body 1 varies with its use.In case of a stylet for superior vena cava, the stylet body 1 preferablyhas a length 300 mm and is bent at an angle of 10° to 15° at a distanceof 12 mm from the distal end 12.

The stylet connector 2 has the stylet body connecting portion 24 where aproximal end 13 of the stylet body 1 is fixed, and a means 23 for fixingthe catheter 3. The connector 2 comprises of a tubular member 20 made ofa metal such as stainless steel or a synthetic resin such aspolypropylene, polyethylene, polyester, ABS resin or the like. Asmall-sized portion 21 of the connector 2 is luer-tapered as indicatedby 21 a to ensure engagement with a connector 31 of the catheter 3having a female luer-tapered shape.

As shown in FIGS. 3 to 5, the stylet connector 2 has a tapered lumen 27,and the stylet body connecting portion 24 is provided integrally andcoaxially with the tubular member 20 so as not to obstruct fluid paths28. Thus, when performing priming procedures, a medical solution fedinto the lumen of the stylet connector 2 is allowed to flow into thecatheter 3 through the paths 28 without removal of the stylet S from thecatheter 3. The stylet body connecting portion 24 has a through-hole 241for insertion of the stylet body 1 coaxially with the axis of thetubular member.

A large-sized proximal portion 22 is provided with a medicine port 25 ofa female luer-tapered shape and has double-start threads 221 close tothe fluid port 25. A suitable injection means such as syringe (notillustrated in the drawings) can be connected to the fluid port 25 toinject a medical solution such as physiological saline or heparinizedphysiological saline into the catheter 3. The double-start thread isintended to connect a lock-type syringe or a lock connector such aslock-type three-way valve to the stylet. In order to make it easy toperform insertion of the catheter 3, the proximal portion 22 may beprovided with a mark 26 indicating the bending direction of the distalend 11 of the stylet 1.

The sleeve 23 is slidably mounted on an outer wall of the tubular memberon the side of the distal end of the connector 2 to prevent the catheter3 connected to the connector 2 from falling away from the stylet. Thesleeve 23 is movable in the direction parallel to the axial direction ofthe tubular member but is prevented from falling away from the tubularmember. The inner wall of the sleeve 23 is provided with female threads231 intended to engage with male engaging means (not shown in thedrawings) such as double-start threads or male screw threads.

As explained above, the stylet assembly of the present invention has thefollowing advantages: (1) The rounded distal end of the stylet enablesto protect the blood vessel from injury by the protruded distal end ofthe stylet when inserting the stylet into the catheter; (2) if thestylet has a distal end bent at a certain angle, it is possible tocorrectly insert the catheter into the blood vessel with ease as thebent distal end minimizes mistakes during insertion of the stylet; (3)the connector with a medicine port makes it possible to perform primingoperations without removal of the stylet being inserted in the catheter,to improve the procedures and to reduce time required for surgicaloperation; and (4) it is possible to avoid fear of secondary infectionas the priming operation can be done without removal of stylet from thecatheter.

What is claimed is:
 1. A stylet assembly for use with a catheter, thestylet assembly comprising: a stylet body to be received within thecatheter, the stylet body having a proximal end and a distal end andcomprising a piece of wire bent double and twisted together to form arounded end at the distal end thereof, the stylet body being bentadjacent the distal end thereof, forming an offset distal end portionfor facilitating correct placement of the catheter into a desired placein a blood vessel; and a stylet connector for connecting the styletassembly to the catheter, the stylet connector comprising (1) a tubularmember having an inflow port at a proximal end thereof and a flowpassage extending through the tubular member between the inflow port anda distal end of the tubular member, the tubular member also having atthe distal end thereof a connecting portion including (1a) a centralthrough-hole in which the proximal end of the stylet body is fixedlyheld and (1b) at least another flow passage within the tubular memberaround the central through-hole and the proximal end of the stylet body,whereby fluid introduced at the inflow port can flow through the tubularbody and into a coupled catheter without removal of the stylet body and(2) means for coupling with the catheter to prevent a coupled catheterfrom separating from the stylet connector during use.
 2. The styletassembly according to claim 1, wherein the stylet connector carries amark which affords an indication of the orientation of the offset distalend portion of the stylet body.
 3. The stylet assembly according toclaim 1, wherein the tubular member includes a first portion and asecond portion integrally formed therewith, the second portion beingsmaller in cross-section than the first portion.
 4. The stylet assemblyaccording to claim 3, wherein the second portion of the tubular memberis externally luer-tapered so as to engage with an internallyluer-tapered connector of the catheter.
 5. The stylet assembly accordingto claim 4, wherein the means for coupling with the catheter comprises athreaded sleeve rotatably carried on the tubular member.
 6. The styletassembly according to claim 1, wherein the means for coupling with thecatheter comprises a threaded sleeve rotatably carried on the tubularmember.
 7. A connector for connecting a stylet assembly to a catheter,the connector comprising a tubular member and means on the tubularmember for coupling with the catheter, and wherein: the means on thetubular member for coupling with the catheter comprises a threadedsleeve rotatably carried on the tubular member; and the tubular memberincludes (1) an inflow port provided at a proximal end of the tubularmember, (2) a flow passage extending through the tubular member betweenthe inflow port and a distal end of the tubular member and (3) aconnecting portion, provided at the distal end of the tubular member,for fixedly holding a proximal end of the stylet body, the connectingportion defining at least another flow passage within the tubular memberand about the proximal end of a stylet body held in the connectingportion, whereby, when performing a priming operation, fluid introducedat the inflow port can flow through the tubular body and into aconnected catheter without removal of the stylet.
 8. The connectoraccording to claim 7, wherein the connecting portion is coaxiallydisposed within the tubular member.